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This study evaluates the clinical effect of foot injection of the bacteria protein Botulinum toxin A on plantar pain in patients with EBS (epidermolysis bullosa simplex) or PC (pachyonychia congenita).

Determination of the difference between treated and untreated foot in change of pressure (measured by manometry) to reach unbearable pain, VAS=8, from baseline to 5 week after injection. [ Time Frame: 5 weeks ]

Secondary Outcome Measures:

Quality of life using a questionnaire (DLQI) [ Time Frame: 12 or 17 weeks ]

Single injection in patients´ soles with Btx A in one foot and sodium chloride in the other, with the possibility of a second injection after 12 weeks. The drug will be given in general anaesthesia after curettage of the focal hyperkeratoses. Only the areas with focal hyperkeratoses will be injected with 50 ul per injection.The active drug Btx A (Dysport®, solution for injection) has a concentration of 100 U/ml, and the maximum dose is 300 U per foot.

Other Name: Dysport®

Drug: Placebo

Placebo preparation without active compound, administered as the active drug.

Other Name: Dysport Placebo

Detailed Description:

Epidermolysis bullosa simplex (EBS) is the most common subtype of epidermolysis bullosa and mutations in keratin genes (KRT 5/14) are responsible for this condition. Painful blisters and keratoderma of the feet are common and the blisters in EBS typically get worse in the summer due to sweating and increased environmental heat. Since 2010, also the related condition pachyonychia congenita (PC) is included in the study. The primary objective of the study is to evaluate the clinical effect of Botulinum toxin A (Dysport®), injected in the foot, on plantar pain in patients with EBS or PC. Quality of life, pain in feet, effect duration, plantar sweating and safety of the treatment will also be studied.

Eligibility

Information from the National Library of Medicine

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